Safety of horizontal curves on rural two-lane roads in Norway




accident prediction model, horizontal curve, negative binomial regression


Horizontal curves are found on all roads. The relationship between the characteristics of horizontal curves and the number of accidents is complex and no previous study has included all factors that are potentially influential for accidents. This paper presents a study of 63 969 horizontal curves on rural two-lane roads in Norway. Accident prediction models including more characteristics of horizontal curves than used in any previous study were developed. Most of the characteristics were found to be related to the number of accidents. Most coefficients were consistent with those found in previous studies, but some findings were surprising. Compound curves, which are curves in which radius varies throughout the curve, were found to be safer than circular or nearly circular curves. A steeper slope of a vertical grade before a curve is associated with fewer accidents.


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Author Biographies

Rune Elvik, Institute of Transport Economics, Norway

Rune Elvik has been a road safety researcher at the Institute of Transport Economics since 1980. His main areas of research have been evaluation studies, meta-analysis and cost-benefit analysis. Rune Elvik served as editor-in-chief (together with Karl Kim) of Accident Analysis and Prevention from 2005 to 2013. He has participated in many European projects and contributed to the Highway Safety Manual. He has published more than 150 papers in scientific journals.

CRediT contribution: Conceptualisation, Formal analysis, Methodology, Writing—original draft, Writing—review & editing.

Espen Strandvik Haugvik, Innlandet county, Norway

Espen Strandvik Haugvik works with traffic safety in Innlandet county council in Norway. He was previously affiliated with the Norwegian Public Roads Administration, where he worked with accident analyses and in-depth investigations of serious accidents. He is currently leading a project in Innlandet county council that deals with safety measures in curves with an assessed high risk. Espen Strandvik Haugvik has an education in sociology from the University of Oslo and a master degree in road engineering from NTNU in Trondheim.

CRediT contribution: Conceptualisation, Data curation, Formal analysis, Writing—review & editing.


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How to Cite

Elvik, R., & Strandvik Haugvik, E. (2023). Safety of horizontal curves on rural two-lane roads in Norway. Traffic Safety Research, 4, 000026.



Research articles